Air separator



Jame 16, 5925. 31,542,05Q

G. H. FRASER AIR SEPARATOR Original Filed March 8, 1919 2 51 1 51 1 V y I //v 4mm? ZWM 3 June 16, 1925.

G. H. FRASER AIR SEPARATOR Original Filed March 8, 1919 2 Sheets- Sheet 2 useful Improvements in Air Separators, ofv

Patented June 16, 1925.

UNITED STATES- PATENT OFFICE.

GEORGE HOLT FRASER, OF BROOKLYN, NEW YORK.

AIR SEPARATOB.

Application filed March 8(1919, Seiial No. 281,445. Renewed September 19, 1924.

To-aZZ whom it may concern:

Be it known that I, GEORGE HOLT FRASER, a citizen of the United States, residing in the borough of Brooklyn, county of Kings, city and State of New York, United States of America, have invented certainnew and which the following is a specification.

This invention relates to for separating fine from coarse material,

and aims to provide certain improvements therein.

Heretofore air separators have comprised .a casing enclosing a chamberpan upper receptacle therein having upper and lower openings communicatingwith the chamber, a lower receptacle having an open upper end below and spaced apart from said lower opening andserving as a tailings cone for receiving coarse material therefrom, and affording communication between the receptacles for air returning from the outer chamberto the lower opening, a revolving distributing disc for feeding material to be separated 1nto the upper receptacle, and a revolving fan above the upper receptacle for causing air to flow upwardly therethrough and outwardly into the chamber to float out line material to the chamber where it may precipitate and whence the air may return etween the receptacles.

My present invention relates particularly to separators of this character and aims to prevent floating particles from returning between the receptacles, to facilitate adjusting the space through which return current may flow, to simplify such devices, and to provide various improvements th rein- To this end in carrying out the; preferred embodiment of my present improvements I provide .foraminous means surrounding the space between the receptacles for intercepting floating particles 1n the current approaching such space, and I preferably provide a valve or means-for varying the space through which current may pass through said foramlnous means, and 1- preferably provide a stationary lower receptacle inwardly'of said foraminous means and said valve and which serves as an upper wall for the lower part of said outer chamber and a lower wall for said return passage, and I preferably provide said valve as a vertically adjustable ring or cylinder within said annular means and between the latter and surrounding said lower receptacle, and I prefair separators ceptacle and, adjustable toward the lower receptacle to vary the space between them,

and I provide various other features of improvement, all of which will be more fully ereinafter set forth with reference to the accompanying drawings, in which- 'Fig. 1 is a vertical axial section showing the preferred adaptation of my present improvements as applied to an inside blower air separator cut on the planes of the lines 11 in Fig. 2, and

Fig. 2 1s a fragmentary horizontal sectiocrii thereof cut on the lines 2-2 in Fig. 1, an

Fig. 3 is a fragmentary vertical section showing a modification, and

Fig. 4 is a diagrammatic view. showing my improved system and the connections and valves between the complementary parts thereof for regulating and controlling the operation of separating material:

Referring to the'drawings A is the casing of an air separator, B is the driving mechanism, C is the feed hopper, D is the distributor, E is the blower, F is the feed chamber,

G is the outer chamber, H is the dust chamber, I is the return passage, J is the tailin s chamber, K isthe upper receptacle and li is the lower receptacle.

The casing A usually has a flat top a, a. cylindrical body 6 and a conical bottom 0.

he driving mechanism usually comprises a bearing frame M, a tubular shaft N, which revolves therein and carries the disc D and surrounds the adjustable feed pipe 0 which delivers'the material to be separated on to the disc D, which latter is vertically adjustable on the shaft N. The blower E generally comprises outwarly adjustable tan ential plates 03 carried from and revolved %y the shaft N.

l"he up er receptacle has a wide or cylindrical bo y P, a contracting upper opening or neck Q, and a lower opening R, and is usually formed with an upper conical wall e,'and a flat top or shelf f below the fan affording above the shelf an annular space or clearance for the latter, and an annular outlet or passage S for current from the up er opening Q, to the outer chamber G, an affording below the shelf an annular recess 9. The bottom of the upper recepta cle is usually a tapering or conical wall it.

The lower receptacle is a cone usually spaced below the upper receptacle and having an open upper ends affording communication fromthe outer chamber to the lower opening R, so that when the fan operates air can circulate through the upper receptacle and its upper opening and the outlet S to the chamber G and descend around the upper receptacle, and dust may precipitate in the chamber H and the air return between the receptacles to the lower opening.

According to one feature of improvement I provide means as the filter T for intercepting particles in the air floating from the outer chamber toward the return passage I between the receptacles, preferably providing a plurality of annular rows of vertically extendin spaced troughs i surrounding the space between the receptacles and affording an annular interstitial wall for the inner side of the outer chamber, the troughs having concave or hollow outer faces j opposed to the inflowing current and affording vertically extending ways through which intercepted material may descend through and out of the current zone to the dust chamber without being molested by adjacent air currents, and being spaced or disposed to afford between their edges vertically extending apertures affording horizontally or inwardly extending current passages through which current may flow intermediate of said ways. Preferably two rows of such troughs are provided and the troughs of the inner row are staggered in relation to those of the outer row so that their hollow faces are opposite the spaces between the outer troughs. The hollows of these troughs serve to hold relatively motionless air in the path of the approaching current, so that any floating particles entering this calm may precipitate therein, and the current passing from the outer chamber to the return will be correspondingly cleaner.

These troughs are preferably mounted on or around the cylindrical part of the upper receptacle by being mounted on sectional are shaped angle irons Z suspended removably from the latter in such way that the horizontal leg of the angle covers and closes the tops of the troughs to prevent current descending vertically between them, the troughs being bolted to the vertical leg of the angle, so that. each trough, each row or any sections, can be removed.

The lower receptacle or tailings cone J is preferably stationary and disposed at the maximum distance desired below the upper receptacle, and its upper end preferably projects an appreciable distance above the lower ends of the filter troughs T, so that it serves as an upper wall for the dust chamber H within these troughs to isolate the chamber from the return current as well as to receive and conduct outwardly coarse material descending from the upper receptacle. The-lower receptacle is preferably formed of a fixed upper section m and a fixed lower section n separably connected together, the upper section being preferably mounted by posts 0 on the upper part 1) of the conical bottom 0 of the outer casing and the lower section at being separably or stationarily mounted by brackets g onthe lower section 1' of the bottom of the outer casing so that the lower removable bottom 1- of the outer casing and the lower section 1 of the tailings cone may be removed together, but are separable so that the lower section of the tailings cone may be assembled previously to applying the outer bottom.

According to another feature of improvement I provide means for varying the space within the filter T through which current may flow to pass between the receptacles, preferably providing v'alve U within the filter T and surrounding the upper open end of the lower receptacle.

By raising the valve U the location of the outlet from the chamber G for return current may be varied and the space through which return current may flow may be diminished, to regulate the current to suit particular requirements of use. The valve U is shown as a ring orcylinder fitting adjustably and loosely in the annular space between the lower receptacle and the filter T, so that it affords a return current passage between its upper edge and the upper receptacle, while its body within the filter tubes deters current from flowing between the lower portions of the latter, and its lower part projecting in the dust chamber serves as an annular wall around the upper part of the tailings cone to prevent eddying currents from approaching the bottoms of the filter tubes.

This valve U may be adjusted in any suitable way, but I prefer to sustain it by adjustable feet It projecting outwardly beneath the filter and carried by, cables u out-- wardly of the latter which are wound on adjusting shafts 4; extending through the recess 9 on each side of the receptacle K so that by turning these shafts with the hand-wheel w the damper U may be raised at four points to move it uniformly. A ratchet z" is provided for locking it. The cables u bein outside the filter have easy access for strlking or grasping or rattling them to move, and thus jar or shake the damper toinsure its proper descent. The brackets 21 serve as feet to bear on the outer cone 0 when the damper is in its lowermost position, and they are provided with additional holes 2 so that the damper may he bolted higher or lower on the feet to vary its initial sition for adjustments additional to t e range of movement of the brackets. The brackets are preferably exa vertically adjustable lit tended to form guides for the damper so that their outer ends slide against the cylindrical wall 6. to preserve the damper in position between the filter and the tailings cone. it

According to ment I preferably provide a damper V outside of and surrounding the filter trqughs and vertically adjustable to vary the inlet thereto. This preferably consists of a ring or cylinder surrounding the lower ends of the filtertroughs at the same height as the upper edge of the damper U and movabletherewith, and as shown is mounted on the feet t and adjustable upwardly toward the upper'receptacle and this'has the function of deterring air currents from flowing inwardly toward the lower part of the troughs to reduce tendency these, and prevent molestation of the particles descending therein, and the space'between the'inner and outer dampers serves as a confined annular conduit for conducting dust discharged by the tubes into the calm of the lower dust chamber and isolating the lower end of the tubes from the strong currents above.

According to another feature of improvement I provide a valve W surrounding the outer part of the upper receptacle and adjustable downwardly toward the inner side projects out-- of the lower receptacle which wardly of it, so that this valve may vary the space between its lower edge and the inner receptacle through which return current may pass. This valve is preferably mounted within the filter and between it and the upper receptacle to vary the inlet through the filter to the return passage, and is preferably mounted on the other end of the cable '11 and operated by the shaft '0 on which the cable is fixed so that theupper valve W has the tendency to counterbalance the lower valve U and they preferably work simultaneously in opposition when used together and not operated independently, and each is independently adjustable as by the turn buckle w in the cable. This legof the cable u passes through the shelf afforded by the angle irons or segments Z' suspendiu the filter tubes, one of which segments is hinged or pivoted so that its section of filter tubes mav be swung outwardly to give access to this valve and serves as a door through the filter when the valves are adjustcd or removed from the path of this section.

According to another feature of improveiment I provide a bifurcated'tailings outlet X with an adjustable .valve :1: as a swinging or flapper valve therein by which the discharge can bedivided as desired between the two legs or confined to one or the other leg so that=either leg may be used for'nornial discharge and the other for testing or another feature of improveto upward eddies in" measuring purposes, or the discharge may be ap ortioned between a plurality of receptac es.

According to another feature of improvement I provide a testing or measuring fine outlet Y comprising a swinging damper and door Z by which the fine discharge may be divert-ed through the opening a when the damper is thrown to the closed position as shown in dotted lines, in moving to which its handle will automatically open the door 6' which is fulorumed on its shaft with a lost motion so that the handle will strike and lift the door as the damper closes and permit the door to close by gravity as the damper opens. a

My invention also provides means to position the filter troughs yieldingly and adjustably and for jarring them impactively, and preferably for this purpose screws 0 engage their lower ends and are drawn outwardly by springs d surrounding them outwardly of the casing and reacting against the latter and theirouter heads 6, so that by turning the screws the lower end of the filter can be centered to suit and held in resilient condition, and from time to time the operator may hammer on the heads of the screws to jar the filter tubes and through them the valves V and U and the lower receptacle to free them from adhering parholes. The upper receptacle is movably sustained op brackets f, which are removable so that the upper receptacle and filter can be lowered through the conical bottom p when the lower cone 1- is removable, and the lower part of the lower receptacle is preferably carried fixedly on and removable with the lower part 1" of the lower cone and the upper part of the lower receptacle is preferably fixed removably on the upper part p of'the lower cone, so that access to the lower receptacle which is separable may be had by "removing its lower part with the lower part 4'- of the casing without disturbing the upper parts.

The feeder disc is preferably vertically adjustable from without the casing, and while revolvingif desired to vary the vertical distance through which material must be lifted, and in operation, this disc being disposed at the desired point, material is fed into the upper receptacle, and the upward current floats the fine material into the outer chamber, Where the fine particles precip tate and the' air current flows through the filter and the return space between the valves U and W and the upper receptacle to the lower opening R.

The filter tubes extract particles floating in the return air and deposit them in the dust chamber, the current justing the dampers U and W to vary the space through which the return current may pass and the speed ,of the fans or the prois varied by ad- &

tive spouts or coarse and line outlets and simultaneously or successively the feed disc D and fan E are adjusted from without the casing to produce the desired results or to adapt them or either of them to varying conditions, and adherence of material to the filter is reduced by vibrating the tubes.

The casing is suitably supported as by outer feet g" and access through the top is provided with one or more suitable hinged or removable manhole covers k affording access inwardly and outwardly of the upper receptacle, and through the side by hinged wall or cover z" affording an opening to the outer chamber G, and access within the lower receptacle from below is afforded by a hinged door or cover j on the lower cone 1- leading into the space around the tailings cone, from which one can disconnect and raise the upper segment m up against the upper receptacle until sufficient room is afforded between the segments of the tailings cone for one to enter.

I preferably mount the hub is of the 'fan above its spokes and slidingly mount the feed disc D concentrically of and supported from the driving shaft N so that it can be adjusted vertically by screw threaded or other means to vary the vertical distance through which the material must be lifted from the disc to the fan, or to vary the space between the disc and the surrounding tapering portion of the feed chamber through which the upward current may flow, or to vary the fineness or quantity of the separated material, so that by screwing the feed disc up or down its position can be varied as desired to suit conditions.

but I prefer to fix the fan hubk' in position on the driving shaft N, and to movably sustain. the feed disc D from the driving shaft N by suspending it therefrom so that it can be rotated thereby and moved vertically relatively thereto. In the construction' shown in Fig. 1 I set the-fan hub k fixedly on the driving shaft and mount the tubular hub Z of the feed disc slidingly on or around this shaft below the fan hub, and I sustain the hub Z therefrom by a screw threaded connection, as by vertically-adj usting bolts m adjustably sustained by revolving screw threaded nuts f sustained by and This y can be accomplished in any suitable way,

revoluble with and rotative relatively to the driving shaft, so that the disc can be easily adjusted from above by adjusting the screw threaded connection by which it is sustained.

A flexible elastic or yielding strip a is preferably mounted on the upper edge of the lower receptacle for making a flexible joint between this cone and the filter, as by sliding on the inner damper U to prevent up-flowing currents around the lower receptacle, and I preferably provide collapsible means as the flexible fabric 0 between the lower receptacle and the damper U and between the damper U and the filter to retard up-flowing currents or preventileakage between these; a'nd I preferably provide floating dampers .p' at the bottom of the filters of fabric or other suitable material to swing upwardly and close the space between adjacent filter tubes in case up-flowing current should be induced through these.

In its preferred form my invention also provides reverse hollow troughs or conduits below the lower ends of the upper troughs and having their concave faces under these to serve as conduits for receiving material therefrom and conducting it downwardly, and having their convex backs r opposed to the inward current to prevent this from molesting descending particles until they have been conducted out of the zone of such currents. 7

According to another feature of improvement my invention preferably provides an adjustable upper receptacle K and a stationary top shelf f, so that the latter affords a uniform current outlet S, while the former may be adjusted either with the disc D to vary the vertical distance through which material must be lifted to the outlet, and relatively to the disc I) to vary the space between the inclined face and the disc through which current must pass to regulate the intensity of such current at this point. The inclined bottom ll. of this ad j-ustable receptacle may be used to vary the return current space when as shown the upper receptacle is not movable with the lower receptacle Z. but-in the construction shown I prefer to utilize the upper inward valve \V for determining the space above the lower receptacle and making the upper receptacle movable independently of this valve. so that the latter may be used for this space and the upper receptacle may be lifted at will and then this space adjusted o suit. The upper and lower walls of the upper receptacle may move together when 1n fixed connection through its intermediate cylindrical wall P as shown, in which case all may be guided by the vertical guide or arm of the bracket f and the upper receptacle will slide on this arm, its upper open end being guided within the telescopic or expansible joint 23' connecting it with the shelf f. The upper receptacle or any of its movable walls ,may be adjusted in any manner as by a cable u operated by a' screw o and hand-wlieel 20 from without the casing. With. this arrangement I prefer to mount the filter segments on the'arms of the brackets f around the upper re ceptacle so that the filter will be independent of movements of the latter.

According to another feature of improvement I provide means .11 hinged to the dampers for swinging, shaking or vibrating them to jar them and the filter and cone for shaking the parts into position or dislodgingl adhering material, and I mount these parts loosely so that these can swing, jar or vibrate. Preferably the dampers are so suspended that they may vibrate or swing in fluctuations of the current to automati cally shake the adjacent parts and thus keep them clear of adhering material, and the lower dampers areso mounted that they have a tendency to move toward the position of maximum opening so that accidental loosening or falling will tend to open instead of close communication through the passages and thus avoid stoppage, and their feet or supports are arranged to aflord clearance for passage of material below them even should they fall to the lowermost possible position.

According to another feature of improvement I preferably provide a revoluble hopper 0 slidingly enclosing the up er end of the feed pipe 0. which is adjusta le therein, the hopper preferably having a through bore 7 clearing the pipe so that the latter may be removed or inserted through the hopper without other disturbance, which affords a top open part 2' in line with the pipe through which access for clearing the latter may be had in operation and a removable cover a preferably closes this opening. Preferably the hopper is provided with a. keyway or slide 6 and the head of a bolt 0 connected to the feed pipe fits this key way and slides therein, and an adjusting screw (1 above the hopper engages this bolt for adjusting the pipe vertically to regulate the feed delivered to the disc.

For regulating the flow of feed to the pipe 0 I prefer to provide an adjustable feed gate adjusted by a screw which controls the inclined inlet conduit 9 to gradually and regularly discharge material therefrom which may be intermittently fed as from the buckets of an elevator not shown or other intermittent sources of supply.

Another feature of improvement cons sts of disposingthe hopper inlet' at one side of and out of line with the 'feed pipe and providing it with one or more spaced. tailings or overflow outlets h and a swinging overflow of tailin s chute i so that overflow or failings may e diverted to either side of the feed pipe and overhead clearance will be afforded above the latter. Preferably a coarse or scalping screen 7' is mounted above the conduit 9 and overlaps the chute 2' so that as material descends through the upper conduit Z on this screen-the latter will extract coarse pieces and these will be deflected or directed around the feed pipe by the chute i A cover m closes the conduit Z and the reversible chute i and an open top wall 0 affords a surface forthis chute to set on, where it is preferably held by a pivotal screw n so it can be swung to either side and make a joint with either side of the conduit and with the opposite outlet opening.

In operation the feed of the hopper being regulated by the gate e and that of the disc being adjusted by the pipe 0, and the volume of current being determined byCadjusting the speed of the fan, of the current opposite the disc is determined by adjusting the inclined wall 6 of the the intensity upper receptacle toward or from the disc.

The distance through which material mustbe lifted is determined by adjusting the disc and this being determined the intensity of the current opposite the disc will then be adjusted by adjusting-the inclined wall of the upper receptacle toward the disc. Variations in the spaces through which current may flow at other points will then be effected to suit by one or more of the valves until adjustments are arrived at giving the product desired. The action of the current on the movable or vibrating parts will cause a vibration tending to keep the surfaces normally free from adhering particles, and occasionally the parts will be violently agitated from without for complete clearing, or for insuring their movement to proper positions. The hopper will be turned toward the source of supply and the overflow shifted to suit desired discharge, and adjustments and tests may be made during operation.

It will be seen that this invention provides various improvements in separators which can be readily and advantageously availed of, and it will be understood that the invention is not limited to the particular details, arrangements, combination of features, or uses, set forth as embodying the preferred form of my invention, since my improvements can be availed of in whole or in part according to such modification as.

walls P sliding in it to vary the cod cham ber F. .The lower receptacle L is here. vertically adjustable and slides in a stationary guard wall U to vary'the tailings chamber J. The upper valve W and lower valve V Work oppositely and the seals t are carried on the valve V and close the spaces between the troughs and the guard U.

The lower reverse troughs q are preferably hinged to the tips of the upper troughs so that they can swing inwardly and also outwardly until their lower ends rest on the lower conical bottom, and they afford spaces between them through which the current can flow into the dust chamber. hinged gravity damper 1" on the end of the upper tube fitting the concavity of the lower tube opens permitting descent of dust and closes against tendency of current to-.rise. The bottoms of both rows of troughs are preferably mounted removably on rings or ring segments 8 and the spaces between them are preferably closed against up current by a seal 25, preferably notched fitting the space between the tubes and mounted on the inner valve U and intermediate valve 14 Covers m and p are reversibly hinged to the chute 2' is an annular spacer for the bolts 0 The gate 0 protects the, disc I) from the weight it would carry if the pipe 0 were full by limiting the feed to that which the pipe is adjusted to discharge.

The brackets f are preferably pivoted to swing on and be vertically adjusted by screws o to vary the outlet S by lifting the shelf f, and are clamped by screws e0 The upper body preferably has a fixed skeleton construction consisting of rings 00 connected by braces 3 on which half of the shell is stationary and the other half is hinged on a vertical rod 2 the upper hinged half a and the lower hinged half I) meeting in a flat joint 0 so that either can be swung open separately from the other, and the lower half having a similar fiat joint (i at the bottom so it can be swung free from the outlet pipe I.

The bolts mf are preferably simultaneously adjusted by a gear 0 engaging their tooth nuts 7.

I preferably make the fan blades expansible, as by a supplemental sliding vane 7 operated through a link 11. and a lever i from a ring 9''" by screws 10 having tooth nuts Z simultaneously operated by a gear 111 carried by the fan hub and a spring n which presses the ring against the screws.

These parts are preferably adjusted from without the casing while running, by any suitable means, as for example by a friction lever 0 operated by an outer handle 7) and engaging the gear e to adjust the feed disc, and by a friction lever q operated by an outer handle 9" and engaging the gear at to adjust the fan blades.

For alternately separating materials requiring known differences of lift distances I preferably provide a two phase or multiple position feeder which is quickly shifted from one to another vertical position, as by mounting .it with a lost motion. This is preferably done by sustaining the disc I) movably on the hub by a ring a and cam It so that when the cam is raised above the dead center the disc will be at the normal high position and when the cam is dropped the disc will drop to the normal low position, other-adjustments being made as to either position as before described.

Preferably the disc D is vertically adjustable relatively to the hub for varying its space from the latter, as by mounting it on a ring at operated by a cam gt o raise or lower the disc on the hub to suit requirements.

Preferably the disc is shifted while running as by operating the cams from rods connected to a ring a operated by a by-path forked lever w from without the casing by a handle m.

Some materials require paddles on the distributing disc, and to provide for quickly utilizing these I preferably mount spaced paddles 3 on a supplementary movable or removable upper feed ring 2 which may be bolted to the feed hub as shown in dotted lines in Fig. 1, when the paddles are not used, or bolted to the disc D, as shown in full lines in Fig. 1, when these paddles are used, and it and the paddles are movable downwardly on to the disc to then afford a supplemental disc with radiating vanes for distributing the material and agitating it while affording current spaces between the blades. The paddle ring is preferably normally removably sustained on the feed hub by bolts a which can be removed and used to clamp it to the feed disc when this is required.

The feed disc is preferably provided with a central outlet 6' normally closed by a door 0 automatically 0 ened to relieve excessive load, as by trip 4 operating its latch .0? when the gate descends and thus releasing it. As shown the feed disc is yieldingly mounted on springs 4 so that it can descend under abnormal welght, thus bringing the trip d against the stop 9, which itself is preferably carried by a rod h shown as extending loosely through the feed tube and ending in a handle a" above the hopper, by which handle can be operated to open and close the door a", which latter swings on a bin e j.

- y invention preferably provides means for automatically regulating the feed, as by utilizing the weight on the feed disc to vary the feed gate which is preferably done by operating a wedge it under the screw 7' by a lever Z sustained and operated by the rod it so that as this rod is pulled down product back to the with the descent of the disc D it withdraws the wedge and lowers the feed gate, thus diminishingfeed until the disc is able to dis tribute it as fast as received, so that the separator can automatically regulate itself and excess will back up in the feed hop er and after filling the latter will overfl dw through the to outlet which then serves with the by-pat o communicating around the casing and connected with the coarse outlet for returning the scalpin s, the overflow if any and the tailings, com ined to a pulverizer (not shown) for other treatment,- an elevator (not shown) being connected to receive supply and refeed it'to the hopper, and a storage bin p being provided as a part of an endless circuit to serve as a reservoir for storing temporary excess, in which circuit the separator and the byath'are arranged in multiple so that eit ermay be use to cut out the other without stopping the circuit, or they may be jointly. used, one to separate and the other to by-path excess and oversize material. This is shown in Fig. 4, where the valve shunts or-divides discharge from the elevator 1" between the two separators, and like valves 8 and t apportion their tailings and fresh feed between the two pulverizers a, and the measuring fine discharge '0 controls the measuring fresh feed inlet w, from the bin 2: to proportion fresh feed to finished discharge, by the means illustrated in my application' Serial No. 722,233 filed Sept. 25, 1912, for example. The by-path 0* is pref erably provided with an automatic valve 3 normally closed to send all material through the separator or automatically opened by the closing of the gate e to then divert all material around the'separator.

at is a chute communicating between the fine outlet and the bin p for diverting fine system for re-se aration. a is a by-path chute for diverting all or part of the material around the pulverizer, and b" is a valve for isolating the pulverizer and returning material to the elevator for re-passage throu h the separator-for further extraction of its fine content in case the separator has left an undue proportion of fines in the returnin tailings, which can be cleaned by thusivert- 1n the material around the pulverizer until all fines are extracted from it before refeeding to the latter. 3 is a colla sible cloth dam er around upper part 0 the filter whic descends with the damper W in opposition to the lower dampers, and k is a removable partition enclosing the. space above the filters.

The feed pipe 0 is normally non-rota so that material descending through it wi I not be subject to any centrifugal force tending to hold it against the inner wall of this threaded means (2 and this combined material with fresh .fan and feed disc,

pipe, but this pipe is slidingly keyed within the neck of the hopper C so that it can be turned with the hopper as the latter is adjusted to suit the source'of supply of material to be separated, while the pipe can be adjusted vertically, by the screw d which are disposed around it and sustain it from the hopper, toward the disc D to regulate flow of material from the pipe to the disc. The stationary feed pipe 0 is concentric of the revolving disc D and should be adjusted vertically to approximately follow the vertical adjustments of the disc, and additionally to regulate flow of; material from the 30 pipe to the disc. The feed disc D,is sustained from above, around the non-rotary feed pipe, iii any suitable manner so that it can be revolved opposite this pipe to distribute the feed it receives therefrom, and can be adjusted vertically relatively thereto to vary the vertical distance between the disc and the fan shelf 7" for any of the purposes described. The disc may be thus rotatively and vertically movably mounted around the stationary feed pipe in any suitable or desired way and sustained from any suitable support,

but when the disc is mounted to revolve with the fan as shown I prefer to sustain it on the tubular driving shaft N slidingly. around the stationary feed pipe, so that the disc can be screwed vertically relatively to the shaft while it will participate in the revolution of the shaft, so that any variation inthc speed of revolution of the shaft N is imparted to both the fan hub and feed disc.

Although I have shown a stepped pulley on the drive shaft B for varying the speed of revolution of the tubular shaft N and its driven parts, and bevel gears for driving the shaft N from the shaft B, it will be undcrstood that any suitable variable speed or speed changing means may be employed, and any desired driving connection may be utilized for communicating motion to the or for varying their speed; and although I prefer to revolve the fan and feed disc similarly and from the one tubular drive shaft N, instead of differentially from independent shafts, it will be understood that my improvements are not limited to this preferred utilization thereof.

The screw threaded nuts f for vertically adjusting the feed disc, are shown as mounted inside of the casing a and resting on top of the fixed fan hub 71: of the tubular vertical shaft N, and as subject to operation from without the casing by a lever 0 oper ated by an external handle frictionally or otherwise'separably engaging the rack 0 to retard it and thus cause the nuts to turn relatively to the screw threaded disc sustaining members m" on the upper ends of which they screw, but any suitable or desired means around the feed pipe and which will adjustably sustain the feed disc from the drive shaft so that it can be adjusted vertically from above the fan, and preferably from without the casing, may be employed, and such means may be in whole or in part located where convenience declares, although the tubular telescopic sliding mounting of the disc hub l relative to the tubular shaft N and around the feed pipe 0 is most convenient in the COIlSil'llCtlOIlj shown.

Likewise the fan varying means, and the means for quickly shifting the position of the feed disc, may be any known or suitable means and either may be disposed whei'e desired, but I prefer the means shown and prefer to dispose each of them within the casing, instead of without it, and to provide means without the casing communicating with them respectively for operating them from without the casing during operation, whereby my improved process of varying the volume of the separating current in its endless path, and of correspondingly or simultaneously varying the point of distribution of the material in the endless current, while feeding material thereto, and while separating the fine material floating therein, may be easily and successfully carried out to vary fineness, change capacity, or suit conditions.

What I claim is:

1. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings communicating with said chamber, a lower receptacle within said casing having an open upper end spaced from said upper receptacle and affording communication between said chamber and said lower opening, means for feeding material to be separated into said upper rece tacle, means for causing a fluid current to ow through said upper receptacle into said chamber and return between said receptacles to said lower opening, a filter for intercepting particles floating in such current from said chamber toward said lower opening, a valve sustained externally of said upper receptacle and surrounding said lower receptacle for varying the s ace through which return current may pass from said outer chamber, and means without said upper receptacle and above said filter for operating said valve.

2. In combination, a casing enclosing a chamber, an upper receptacle within said casing having up er and lower openings communicating wit said chamber or wall, a lower receptacle within said casing having an open upper end s aced from said upper receptacle and afl'ordin communication between said chamber an said lower opening,

:opening,

means for feeding material to be separated intosaid upper receptacle, means for causing a fluid current to flow through said uper receptacle into said chamber and return tween said receptacles to said lower opening, a filter for intercepting particles floating in such current from said chamber toward said lower opening, and an adjustable valve surrounding said filter for varying the space through which return current may flow thereto.

3'. In combination, a casing enclosing. a chamber, an upper receptacle within said casing having upper and lower openings communicating with said chamber and having an upper cylindrical outer part, a lower receptacle within .said casing having an open upper end spaced from said upper receptacle and affording communication between said chamber and said lower opening, means for feeding material to be separated into said upper receptacle, means for causing a fluid current to flow through said upper receptacle into said chamber and return between said receptacles to said lower floating in such current from said chamber toward said lower opening, and. a valve surrounding and sliding vertically on the cylindrical part of said upper receptacle and adjustable downwardly toward the in ner face of said lower receptacle for varying the space between said receptacles through which return current may pass.

4. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings communicating with said chamber, a lower receptacle within said casing having an open upper end spaced from said upper receptacle and affording communication between said chamber and said lower opening, means for feeding material to be separated into said upper receptacle, means for causing a fluid current to flow through said upper receptacle into said chamber and return between said receptacles to said lower opening, a filter for intercepting particles floating in such current from said chamber toward said lower opening, and a valve within and a valve without said filter for varying the space through which current may pass.

5. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings communicating with said chamber, a lower receptacle in said casing having an open upper end spaced from and extendin downwardly of said lower receptacle an affording at its outer edge an inlet communicating from said chamber between said receptacles to said lower opening, a valve between said receptacles disposed inwardly of said outer edge and intermediate of said inlet and said a filter for intercepting particles lower opening for varying the .space between said receptacles through which can rent returning from said chamber may pass to said lower opening, means for causing a fluid current to circulate upwardly through said upper receptacle into said chamber and return between said receptacles to said lower opening, and means for feeding material tobe separated into said upper receptacle.

6. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings communicating with said chamber, a lower receptacle in said casing having an open upper end spaced from and extending downwardly of said lower-receptacle and affording at its outer edge an inlet communicating from said chamber between said receptacles to said lower opening, means for causing a fluid current to circulate upwardly through said upper receptacle into said chamber and return between said receptacles to said lower opening, and a cylindrical valve mounted on said upper receptacle remote from said lower opening and above and adjustable downwardly toward said lower receptacle for varying the space above the latter and below said valve through which current may flow between said receptacles.

In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower opcnings communicating with said chamber, a lower receptacle in said casing having an open upper end spaced from and extending downwardiy of said upper receptacle and affording at its outer edge an inlet communicating from said chamber between said receptaclcs to said lower opening, a valvebetween said receptacles disposed intermediate of said inlet and said lower opening for varying the space between said receptacles through which current returning from said chamber may pass to said lower opening, means for causing a fluid current to circulate upwardly through said upper recepta le into said chamber and return between said receptacles to said lower opening, and two valves concentric of said receptacles for varying the space through which current may return from said chamber to the space between said receptacles.

8. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings connnunicating with said chamber, a lower receptacle in said casing having an open upper end spaced from and extending downwardly of said upper receptacle and afl'ording at its outer edge an inlet communicating from said chamber between said receptacles to said lower opening, a valve between said receptacles disposed intermediate of said inlet and Said lower opening for varying the space between said receptacles through which current returning from said chamber may pass to said loweropening, means for causing a fluid current to circulate upwardly through said upper receptacle into said chamber and return between said receptacles to said lower opening, and two similarly movable valves concentric of said receptacles for varying the space through which such current may flow.

9. In combination, a casing enclosing a chamber, an upper receptacle within said casing having upper and lower openings communicating witlrsaid chamber, a lower receptacle in said casing having an open upper end spaced from and extending downwardly of said upper receptacle and affording at its outer edge an inlet communicating from said chamber between said receptacles to said lower opening,- a valve between said receptacles disposed intermediate of said inlet and said lower opening for \varying the t space between said receptacles through which current returning from said chamber may pass to said lowor, opening, means for causing a fluid current to circulate upwardly through said upper receptacle into said chamber and return between said receptacles to said lower opening, and two oppositely movable valves concentric of said receptacles for varying the space through which such current may- 10. In combination, a casing enclosing a chamber, an upper receptacle within saideasing having upper and lower openings communicating with said chamber, a lower receptacle in said casing having an open upper end spaced from and extending downwardly of said upper receptacle and affording at its outer edge an inlet communicating from said chamber between sald receptacles to said lower opening, a valve between said receptacles disposed intermediate fof saidinlet and said lower opening for varying the space between said receptacles through which current returning from said chamber may pass to said lower opening, means for causing a fluid current to circulate upwardly through said upper receptacle into said chamber and returnbetween said receptacles to said lower opening, and two simultaneously movable valves concen tric of said receptacles for varying the space through which such current may flow.

11. In combination, a casing enclosmga chamber, an upper receptacle within said casing having upper and lower open ngs communicatingwith said chamber, a lower receptacle in said casing having an open upper end spaced from and extendlng downwardly of said upper receptacle and aflording at its outer edge an inlet communicating from said chamber between said receptacles to said lower opening, a valve between which such current may said receptacles to said lower opening, and a counterbalanced valve concentric of said receptacles for varying the space through flow.

12. In combination, a casing enclosing a chamber, an upper receptacle insaid casing having upper and lower openings communicating with said chamber, a lower receptacle having an open upper end spaced from said upper receptacle and affordin communication from said chamber to said lower opening, means for feeding material to be separated into said upper receptacle, means for causing a fluid current to flow up through said upper receptacle into said chamber and return between said receptacles, means for intercepting particles floating in such return current comprising vertically extending hollows aflording ways for descending solid particles and intermediate apertures affording current passages be tween said ways, and means intermediate of said ways for preventing current from flowing upwardly through or between said ways.

13. In combination, a casing enclosing a chamber, an upper receptacle in said casing having upper and lower openings communirating with said chamber, a lower receptacle having an open end spaced from said upper receptacle and aflording communication from said chamber to said lower opcmng, means for feeding material to be separated into said upper receptacle, means for causing a fluid current to flowup through said upper receptacle into said chamber and return between said receptacles, means for intercepting particles floatin in such return current comprising vertically extending hollows affording ways for descending solid articles and intermediate apertures afording current passages between said ways, and means in said apertures for preventing current from floating upwardly and inwardly of said filtering means. 4

14. In combination a casing enclosing a chamber, an upper receptacle in said casing having upper and lower openings communicating with said chamber, a lower receptacle in said casing affording a return current passage from said chamber to said upper receptacle and an outlet for coarse material, means for causing a fluid current to flow through said upper receptacle to said chamber and return through said passage, and means afl'ordin'g a fine outlet from said chamber having a damper for diverting the line material, an auxiliary outlet in operative relation to said damper, and a door for said auxiliary outlet operating with said damper.

15. In combination, a casing enclosing a chamber, an upper receptacle in said casing having upper and lower openings communicating with said chamber, a lower receptacle in said casing-affording a return current passage from said chamber to said upper receptacle and an outlet for coarse material, means for causing a fluid current to flow through said upper receptacle and through said passage, means for feeding material to be separated into said upper receptacle, foraminous means for intercepting particles floating in such current toward said return passage, and means for vibrating said intercepting means.

16. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle mounted in said casing and affording a return current passage communicating between said chamber and said lower'opening, means for causing a fluid current to flow upwardly through said upper receptacle into said chamber and return through said passage, means for feeding material to be separated into said upper receptacle, and hinged movable filter means in said casing affording a'foraminous filter for intercepting particles floating in such current returning to said passage movable to aflord a door between said chamber and said passage.

17. In combination, a casing enclosing a chamber, an upper receptacle in said casing having upper and lower openings communicating with said chamber, a lower receptacle in said casing affording a return passage communicating from said chamber to said upper receptacle and an outlet for coarse material, means for causing a fluid current to flow through saidupper receptacle to said chamber and return through said passage, means for feeding material to be separated into said upper receptacle, removable means within said casing affording access within said receptacles and hinged means opposite said removable means affording a swinging door for said casing for affording access to said return passage.

18. In combination, a casing enclosing a chamber and having a tapering lower portion, an inner receptacle in said casing having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and upper opening to said chamber and return through said lower opening, means for feeding material to be separated into said receptacle, removable means within said casing afl'ording access within said receptacles, and hinged means on said tapering communicating therewith, means a conununicating therewith,

portion and opposite saidremovable means affording a door for 'said casing afi'ording access to said receptacle.

19. In combination, a casing enclosing a chamber, a receptacle mounted in said chamber and having upper and lower openings communicating therewith, means afierding a passage for return current from said chamber to said lower opening, means for causing a fluid current to flow upwardly through said receptacle and upper opening into said chamber and return through said return passage tosaid lower opening, means for-feeding material to be separated into said receptacle, and adjustable foraminous means for intercepting particles floating in such current disposed in the path of such (urrent returning from said chamber to said lower opening.

20. In combination, a casing, enclosing a chamber, a receptacle mounted in said chamber and having upper and lower 0 enings ording a passage for return current from I said chamber to said loweropening, means for causing a fluid current to flow upwardly through said receptacle and upper opening into said chamber and return through said return passage to said lower opening, means for feeding material to be separated into said receptacle, and resiliently mounted filtering meansfor intercepting particles float ing in such current disposed in thepath of ow of such current to said lower opening.

21. In combination, a casing enclosing a chamber, a receptacle mounted in said chamber and having upper and lower openings means affording a passage for return current from said chamber to'said lower opening, means for causing a fluid current to low upwardly through said receptacle and upper opening into said chamber and return through said return passage to said lower opening, means for feeding material to be separated into said receptacle, interstitial means for intercepting particles floating in such current disposed in the path of flow of such current to said lower opening, and means for impactively arrmg such interstitial means. i

22. chamber, a receptacle mounted in said chamber and having upper and lower openings communicating therewith, means affording a passage for return current from said chamher to said lower opening, means for causing a fluid current to flow upwardlythrough said receptacle and upper opening into sald chamber and return through said return passage to saidlower opening, means for feeding material to, be separated. into said receptacle, and filtering means for extracting floating particles from such current, and means elastically positioning said filtering means.

varying the space through In COD'lblIlRtlOIl, a casing enclosing aadjusting said fan 23. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber,

a lower receptacle afi'ording a return current passage from said chamber to said lower opening, means for causing a fluid current to flow upwardly through said upper receptacle and upper opening to said chamber and return through said passage to said lower opening, means for feeding material to be separated into said upper receptacle, movable means for adjusting the vertical distance through which material must be lifted from said feeding means to said upper opening to regulate the finenessof material carried into said chamber by such current, means for varying the speed of such'current,'means for which such current is permitted to flow. to said lower opening, and means for intercepting partiples floating in such current in the path of uch current flowing from said chamberto said lower opening.

24-. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle mounted in said chamber and affording communication between the latter and saidlower opening, means for feeding mhterial to be separated into said.

upper receptacle, a revolving fan for causing a fluid current to flow upwardly through said upper receptacle and upper opening into said casing and return through said passage to said lower opening, movable means for adjusting said fan to vary such current, and filtering means for intercepting particles floating in such current disposed in the path of such current flowing between said fan and said lower opening.

25. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings comniunicating with said chamber,

afixed receptacle mounted in said chamber and affording communication between the latter and said lower opening, means for feeding material to be separated into said upper receptacle, a revolving fan for causing a fluid current to flow upwardly through said upper receptacle and upper opening into said casin and return throu h said )assa e g is movable means for to vary such current,

to said lower opening,

Cal

means for varying the space through which such current may flow to such lower 0 ening, and means for intercepting particles floating in such current. i

26. In combination, a casing enclosing a chamber,- an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamher, a stationary lower receptacle mounted in said casing in fixed relation to said upper receptacle affording communication from said chamber to said lower opening between said receptacles and aflording a uniform vertical distance between said lower opening and the interior of said lower receptacle through which material from said upper receptacle may descend, means-for causing a fluid current to flow upwardly in said upper receptacle through said upper o 'ening into said casing and return between said receptacles to said lower opening, means for feeding material to be separated into said upper receptacle and means affording a filter for intercepting floating particles in such current flowing from said chamber to said lower opening.

27. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a stationary lower receptacle mounted in said casing in fixed relation to said upper receptacle affording communication from said chamber to said lower opening between said receptacles and affording a uniform vertical distance between said lower opening and the interior of said lower receptacle through which material from said upper receptacle may descend, means for causing a fluid current to flow upwardly in said upper receptacle through said upper opening into said casing and return between said receptacles to said lower opening, means for feeding material to be separated into said upper receptacle, a. vertically adjustable valve above and without said lower receptacle affording communication from said chamber to said lower opening between'its edge and said upper receptacle for varying the space between its edge and said upper receptacle through-which current may pass,

and means affording a filter for intercepting floating particles in such current flowing from said chamber to said lower opening.

28. In combination, a casing enclosing a chamber and having a vertical side portion, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for feeding .material to be separated into said receptacle,

means for causinga fluid current to flow through said receptacle and upper opening into said chamber and return through said lower opening, and vertically sliding means for varying the space through which such current is permitted to flow to said lower opening mounted on said'casing and slidingly sustained by said vertical portion.

29. In combination, a casing enclosing a. chamber, an adjustable upper receptacle mounted in said chamber and having upper and lower openings communicating therewith, a lower receptacle mounted in said chamber and affording a passage for return current communicating between said chamber and said lower opening, a fan revolving in said casing above said upper receptacle for causing a fluid current to flow upwardly through the latter into said chamber and return through said passage to said lower opening, comprising a hub, means within said upper receptacle for feeding material to be separated therein comprising a vertically adjustable revolving disc, a revolving shaft on which said hub and disc are mounted, and means sustaining said disc from and disposed above said hub.

30. In combination, a casing enclosing a chamber, a receptacle therein having upper. and lower openings communicating with said chamber, a revolving fan mounted, in said casing for causing a fluid current to flow upwardly through irough said upper opening to said chamber and return through said lower opening, a revolving feeding disc in said receptacle for feeding material to be separated therein, a vertical shaft carrying said fan and disc for revolvingthem together, a tubular hopper affording communication through said fan to said disc for feeding material thereto, and

a valve in advance of said hopper for regulating flow of material thereto in advance of said disc.

31. In combination, a casing enclosing a chamber, a receptacle in said casing having upper and lower openings communicating with said chamber, a revolving fan in said casing for causing a fluid current to flow up through said receptacle through said upper opening to said casing and return through said lower opening, a revolving disc in said receptacle for feeding material to be separatedtherein, a tubular shaft for revolving said parts, a tubular feed pipe within said shaft for conducting material therethrough to said disc, a hopper enclosing the'upper end of and communicating with said feed pipe for supplying material thereto affording an aperture axially of said feed pipe for access through the latter, and means closing said aperture.

v 32. In combinationja casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a revolving fan mounted in said casing for causing a fluid current to flow up through said receptacle into said chamber and return through said lower opening, a revolving disc in said receptacle for feeding material to be separated therein, a tubular shaft for revolving said fan and disc, an adjustable feed pipe traversing said shaft for feeding material to said disc,a hopper above said pipe and means above said hopper and connected to said pipe for adjusting it vertically relatively to said disc.

33. In combination, a casing enclosing a said receptacle and lower opemngs communicating with said chamber, means for causing a fluid current to flow through said receptacle and upper opening into said casing and return through said lower opening, means for feeding material to be separated into. said' receptacle, a feed pipe communicating from said means to above said receptacle, and a hopper communicating with said feed pipe and having overflow outlet conduits at the side of and out of line with said pipe. b 34. In combination, a casing enclosing a chamber, a receptacle therein having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and upper opening into said casing and returnthrough said lower opening, means for feeding material to be separated into said receptacle, a feed pipe communicating from said means to above said receptacle, and a hopper communicating with said pipe and having a shiftable overflow chute out of line with said 1 e. 35. In combination, a casing enclosing a chamber, means affording a passage for fluid current in said chamber, means for causing a fluid current to flow through said passage, means forfeeding pulverulent material to be separated to said passage, and means for intercepting solid particles floating in said current comprising a plurality of vertically extending hollow troughs affording a foraminous wall in said passage having vertically extending hollows in their faces opposed to said current alfording downward ways for such particles to descend, and hav ing verticallyextending recesses intermediate of-said ways afli'ording current passages, and means for covering the longitudinal ends of said recesses and disposed between said troughs for preventing current entering longitudinally of them.

36. In combinatioma casing affording a chamber, means affording a current passage con'nnunicating with said chamber, means for causing a fluid current to flow through said passage, means for'feeding pulverulent material to be separated into such current, and means for intercepting solid particles floating in such current comprising an interstitial member in the path of such current,

and a vibratorily mounted damper in said casing and in operative relation to said means for varying the space through wh ch such current may flow.

37. In combination, a casing enclosing a current passage, means for causing a fluid current to flow through said passage, means for feeding pulverulent material to such current, means comprising a foraminous wall. in said passage for'intercepting solid particles floating in such current, and swinging means within said casing and affording a valve in operative relation to said wall for varying the space through which such current may pass. I

38. In combination, a casing enclosing a chamber, means affording an annular current .passage in said chamber, means for causing a fluid current to flow through said passage, means for feeding material to be separated to said current, means for intercepting solid particles floating in such current comprising an annular series of vertically extending troughs having concave faces opposed to the approaching current, and a vibratory member in operative relation to said troughs and movable to jar said troughs.

39. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to ow through said upper opening to said casing and return through said lower opening, means for intercepting floating material in said current comprising an annular series of vertically extending troughs affording current passages between their edges, adjustable means for varying the space through said troughs through which current is permitted to circulate, and yielding means making a flexible sliding joint between said troughs and said adjustable means for avoiding leakage of current between them.

40. In combination, a casing enclosing a chamber, an upper receptacle mounted in said chamber and having upper and lower openings communicating therewith, "means for causing a fluid current to flow through said upper opening to said chamber and return through said lower opening, means for feeding material to be separated into said upper receptacle, means for interceptingparticles floating in such current toward said lower opening, a lower receptacle below said lower-opening projecting within said intercepting means and affording a return current passage therein to said lower opening, and yielding means for avoiding leakage of current between said lower receptacle and said'intercepting means.

41. In combination, a-casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber,

-a lower receptacle mounted in said casing and having an open upper end affording a return passage communicatin between said chamber and said lower opening, means for causing a fluid current to flow through said upper opening to said chamber and return between said receptacles to said lower opening, means for feeding material to be separated to said upper receptacle, filtering means in the path of such current for intercepting particles floatingiin such current, and means for. varying the space through which such current is permitted to flow comprising a bodily movable loosely sustained vertical annular valve member.

42. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle mounted in said casing and having an open upper end aifording a return passage communicating between said chamber and said lower opening, means for causing a fluid current to flow through said upper opening to said chamber and return between said receptacles to said lower opening, means for feeding material to be separated to said upper receptacle, and means for varying the space through which such current. is permitted to flow comprising a swinging member affordingbetween itself and said upper receptacle a space.

througlr which said current may pass between said receptacles.

43. In combination, a casing enclosing a chamber, a receptacle therein having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said upper opening to said chamber and return to said lower opening, means for feeding material to be separated into said receptacle, means for intercepting particles floating in such current returning to said lower opening comprising vertically extending hollows afiording ways for such particles todescend across the path of flow of such current, and means within said casing and beneath said ways for preventing intercepted particles from being molested by such current. comprising means affording conduits for such particles below said hollows.

44. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle mounted in said casing and having an open upper end affording communication between said chamber and" -sa1d lower opening, means for causing a fluid current to flow through said upper receptacle through said chamber and return between said receptacles, means for feeding material to be, se arated into said upper receptacle, means or intercepting particles floating in such current flowing from said chamber to said lower opening comprising vertically extending troughs having their hollow faces opposed to the direction of flow of such current, and means for conducting intercepted particles away from such current comprising downwardly extending troughs having hollows on their faces opposed to the hollows of said first troughs and disposed below and in operative relation to the latter to receive precipitate therefrom and conduct it downwardly, said troughs affording between their hollows vertically extending passages for such current.

45. In combination, a casing enclosing a chamber, an upper receptacle mounted in said chamber and having upper and lower openings communicating therewith, a lower receptacle mounted in said chamber and having an open upper end affording com-,

munication between said receptacles-from said chamber to said lower opening, means for causing a fluid current to flow through said upper receptacle and upper opening to said chamber and return between said receptacles through said lower opening, means for feeding material to be separated into said upper receptacle, and means within said casing for arring said lower receptacle.

46. In combination, a casing enclosing a chamber, an upper receptacle mounted in said chamber and having upper and lower openings communicating therewith, a lower receptacle mounted in said chamber and having an open upper end affording communication between said receptacles from said chamber to said lower opening, means for causing a fluid current to flow through said upper receptacle and upper opening to said chamber and return between said receptacles through said lower opening, means for feeding material to be separated into said upper receptacle, a valve for varying the space through which such current may flow, and means for shaking said valve.

47. In combination, a casing enclosing a chamber, an upper receptacle mounted in said chamber and having upper and lower openings communicating therewith, a lower receptacle mounted in said chamber and having an open upper end affording communication between said receptacles from said chamber to said lower opening, means for causing a fluid current to flow through said-upper receptacle andup'per Opening to said chamber and return betweensaid receptacles through said lower opening, means for feeding material to be separated into said upper receptacle, a valve for varying the space through which current may flow, filtering provisions for intercepting particles floating in such current from said chamber toward said lower opening, and means for shaking said filtering means.

48. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle mountedin said casing and having an open u per end affording communication from sald chamber to said lower opening, means for causing a fluid current to circulate upwardly through said upperreceptacle through said upper opening into said chamber and return between Inn said receptacles to said lower opening,

' means for feeding material to be separated into said upper receptacle, and means for varying the space through which such current is permitted to flow tending to move toward a position to increase such space.

49. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said chamber, a lower receptacle having an open upper end affording communication between said receptacles from said chamber to said lower opening, means for causing a fluid current to flow up through said upper receptacle through said upper opening to said chamber and return between said receptacles to said lower opening, means for feeding material to be separated to said upper receptacle, a damper for varying the space through which such current is permitted to pass, and collapsible means connected to said damper.

50. In combination, a casing enclosing a chamber, an upper receptacle mounted in said casing and having upper and lower openings communicating with said" chamber, a lower receptacle having an open upper end affording communication between said receptacles fromsaid chamber to said lower opening, means for causing a fluid current to flow up through said upper receptacle through said upper opening to said chamber and return between saidreceptacles to said. lower opening, means for feeding material to be separated to said upper receptacle, a filter for intercepting particles floating in such current returning from said chamber to said lower opening, and flexible means between said filter and said lower receptacle for preventing current leakage between them. I

51. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings con municating with said chamber, .means for feeding material to be separated'into said receptacle, means for causing a fluid current toflow through said receptacle and upper opening into said chamber and return through said lower opening, means for intercepting particles floating in such current affording two successive foraminous walls in the path of such current, and means for varying the space through which such current may flow disposed intermediate of said walls.

52. In combination, a casing enclosing a chamber, a receptacle therein having upper and lower openings communicating with said chamber, means for feeding material to be separated into said receptacle, means for causing a fluid current to flow through said receptacle and upper opening into said casing and return through said lower openin means for intercepting particles floating in such current comprising a row of spaced hollow troughs affording current passages between their adjacent edges, and means disposed in the spaces between said troughs for preventing flow of current longitudinally between said troughs extending between their adjacent edges.

53. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and upper opening to said chamber and return through said lower opening, means for feeding material to be separated into said casing comprising a vertical conduit, a vertically adjustable revolving disc and a plurality of spaced means disposed around said conduit and for adj usting said disc vertically, and means for simultaneously operating said spaced means to equally adjust said disc.

54:. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for feedingthe material to be separated into said'receptacle, and means for causing a fluid current to flow through said receptacle and one of said openings into said chamber. and return through the other of said openings comprising a revoluble fan having blades variable to vary their superficial area, and means for simultaneously varying said blades.

' 55. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with saidchamber, means for feeding material to be separated into said receptacle, and means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings comprising a fan having outwardly expansible blades to increase their superficial area, and means for simultaneously extending said blades.

56. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for feeding material to be separated into said receptacle, and means forIcausing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings comprising a fan having adjustable blades and means for simultaneously adjusting them.

57. In combination a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings conununicating with said chamber, means for feeding material to be separated into said receptacle, adjustable revolving'means for causing a fluid current to flow through said receptacle and one of said openings into' said chamber and return through the other of said openings, and means within said casing for adjustingsaid revolving means during revolution thereof, and means without said casing for operating said adjusting means.

58. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating withsaid chamber, means for causing a fluid current to flow through V said receptacle and one of said openings into saidchamber and return through the other of said openings, a non-r0tary feed pipe, suspended vertically adjustable revolving means for feeding material to be separated into said receptacle, and means for adjusting said revolving means during revolution thereof.

59. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and havingupper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said-openings, a non-rotary feed pipe,

suspended vertically adjustable revolving means for feeding material to be separated into said receptacle, and means for adjusting said revolving means from without said casing.

60. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings, a vertical feed conduit, a revolving distributor, for feeding material to be separated into said receptacle operative therein in different vertical positions, and quickly shiftable from one to another of said positions, and means around said conduit for quickly shifting said distributor vertically.

61. In combination,,a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings, and revolving means for feeding material to be separated into said receptacle comprising a vertically downwardly yielding feed disc.

62. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means i for causing a fluid current to flow through for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings, revolving means for feeding material to be separated into said receptacle comprising a feed disc having an outlet door, and means for opening said outlet during revolution of said disc.

64. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having'upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings, revolving means for feeding material to be separated into said receptacle comprising a feed disc having an outlet door, and means foropening said outlet from without said casing.

65. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber andreturn through the other of said openings, and revolving means for feeding material to be separated into said receptacle comprising a feed disc and means for automatically relieving it of overloa 66. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of said openings, and revolving means for feeding material to be separated into said receptacle comprising a feed disc and distributing vanes movable into operative relation therewith.

67. In combination, a casingenclosing a chamber, a receptacle mounted in'said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to fiow through said receptacle and one of said openings into said chamber and return through the other of said openings, means for feeding material to be separated into said receptacle,

I means for feeding such material to said feeding means, and means operated by said first feedingvmeans for operating said second feeding means. 3

68. In' combination, a casing enclosing a chamber, 'a receptacle mounted in said caschamber,

.ing means, and adjustable means ing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into'said chamber and return through the other of said openings, means for feeding material tobe separated into said receptacle, means for feeding such material to said feeding means, and means automatically operated by said feeding means controlling flow of said material thereto.

'69. In combination, a casing enclosing a chamber, a receptacle mounted in'said casing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of saidopenings into said chamber and return throu h the [other of said openings, means for ceding material'to be separated into said receptacle,

and means for automatically varying the.

quantity of material fed into said receptacle.

70. In combination, a casing enclosing a a receptacle mounted in said casing and having upper and lower openings communicating with ,said chamber, means for causing a fluid current to flow through said receptacle and one of said openings into said chamber and return through the other of'said openings, means for feeding material to be separated into said receptacle, means for adjusting such feed to said feedforjvarying feed tosaid adjusting means.

71. In combination, a casing enclosing a. chamber,a receptacle mounted in said cas ing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and one of said openings inother of said openings, means for to said'chamber and return throu h the ceding material to be separated into said receptacle, means for restrictin feed to said feeding means, means afior ing a conduit to said restricting means, means afl'ording'an outlet for coarse material from said chamber, and means affording a by-path aroundsaid casing communicating between said conduit and said outlet.

72. In combination, a casing enclosing a chamber, a receptacle mounted in said casing andhaving upper and lower openings communicating with said chamber, means for causing a fluid current to flow through a said receptacle and one of said openings into said chamber and return through the other of said openings, means for feeding material communicating with to be separated intosaid receptacle comprising a relief outlet therewith, means afi'ording, a relief outlet from said casing, means affording a conduit communicating with said feeding means, and means aifording a conduit communicating with said conduit and with said outlet around said casing.

73. In combination, a casing enclosing a chamber, ing and having upper and lower openings communicating with said chamber, means for causing a fluid current to flow through said receptacle and upperopen-ing into sald chamber and return through said lower opening, means for feeding material to be separated into said receptacle, means afi'ording an inlet to said casing for material to be separated, means affording an outlet from said receptacle for coarse material, means affording an oulet from, said casing'for separated material, means for supplying material to be.separated to said casing comprising an endless path for material and a discharge conduit communicating between said path and said inlet, means affording a return conduit communicating between said outlet for separated material and such endless path, and means for diverting separated material from said casing to such endless path for the return of such separated material to said inlet. a

74. In combination, a casing enclosing a chamber, a receptacle mounted in said casing and having upper and lower openings said chamber, means for causing a fluid current to flow through said receptacle and upper opening into said chamber and return through said lower opening, means for feeding material to be separated into said receptacle, means affording an inlet to said casing for such material, means affording an oulet from said casing for separated material, means affording an oulet from said receptacle for coarse ma-, terial, means for supplying to said casing material to be separated comprising an endless path for such material, and a discharge outlet communicatin between'saidpath and said inlet, means atl ording a conduit com municating between said coarse outlet and such endless path, and means for diverting coarse material from said coarse outlet into said conduit for returning such material to said inlet.

75. In combination, a casing enclosing a chamber, a receptacle mounted in said chamber and having upper and lower openings communicating therewith, means for feeding material to be separated to said receptacle, means 'for causing a fluid current to flow through said receptacle and upper opening into said chamber and return through said lower opening, means affording an oulet from said casing for separated material, means afi'ording an outlet from said receptaa receptacle mounted in said cas- 01c for coarse material, means for supplying material to be separated to said casing, means affording a measured inletfor material to be separated to said casing, means affording an overflow passage for material to be separated communicating with said supplying means in advance of said measured inlet, means affording an endless path for material to be separated comprising a discharge outlet communicating with said supplying means in advance of said measured inlet, and means affording a conduit communicating between said overflow passage and said endless path, for conducting excess of such material overflowing from said measured inlet to said endless path for return to said supplying means.

76. In combinatlon, two casings each enclosing a chamber, receptacles mounted in said chambers respectively and each having upper and lower openings communicating with the chamber in which it is mounted, means in said receptacles respectively for feeding material to be, separated thereto, means in said casings respectively for causing fiuid currents to fiow through said receptacles and upper openings into said chambers and return to said lower openings,

means on said casings respectively affording an inlet thereto for material to be separated, means on said casings respectively affording an outlet therefrom for separated material, means below said receptacles respectively affording an outlet therefrom for coarse material, means for supplying material to be separated to both said receptacles comprising an endless path for such vmaterial and discharge outlets communicating between such path and said inlets respectively, means aflording conduits for coarse material communicating between such path and said coarse outlets respectively, and adjustable means between such path and said discharge outlets controlling discharge of material from such path to such discharge outlets.

77 In combination, a casing enclosing a chamber, a receptacle mounted in said chamber and having upper and lower openings communicating therewith, means for feeding material to be separated into said receptacle, means for causing a fluid current'to flow thrgugh said receptacle and upper opening into said chamber; and return through said lower opening, means affording an outlet from said casing for separated material, means affording an outlet from said receptacle for coarse material, elevating means for elevating material to be separated affording an endless path for such material and a discharge outlet communicating between said path and said inlet, means affording a coarse conduit communicating between said coarse outlet and said elevating means, means affording an inlet for fresh material communicating with said coarse conduit between said coarse outlet 'a d said elevating means, and means in the path of such fresh material for resisting inflow t0 the latter during the presence of such coarse material in such coarse conduit.

7 8. In combination, a casing enclosing a chamber, a receptacle mounted in said chamher and having upper and loweropenings communicating therewith, means for feeding material to be separated into said receptacle, means for causing a fluid current to flow through said receptacle and upper opening into said chamber and return through said lower opening, means affording an outlet from said casing for separated material, means affording an outlet from said receptacle for coarse material, means affording an endless path through and without said casing communicating with and receiving coarse material from said coarse outlet and communicating with and returning such coarse material to said inlet, means for supplying fresh material to be separated communicating with such endless path, and means in such endless path for retarding supply of such fresh material thereto during the presence of such coarse material therein. 4

79. In combination, a casing enclosing a chamber, a receptacle mountedinsaid chamber and having upper and lower openings communicating therewith, means for feeding material to be separated into said receptacle, means for causing a fluid current to fiow through said receptacle and upper opening into said chamber and return through said lower opening, means 'aff'ordlng an inlet to said casing for material to be separated, means affording an outlet from said casing for separated material, means affording an outlet from said receptacle for coarse material, elevating means affording an endless path for material to be separated and comprising a discharge outlet communicating with said inlet, means affording communication between said coarse outlet and said elevating means, meansuaffording a source of supply for fresh material communicating with said elevating 'means, means affording communication between said discharge outlet and said source of supply, and movable means for appor tioning between said inlet and said source of supply material discharged from said discharge outlet.

80. In combination, a casing enclosing a chamber, a receptacle mounted in said chamber and having upper and lower openings communicating therewith, means for causing a fluid current to flow through said receptacle and upper opening into said chamber and return through said lower opening.

means for feeding material to be separated into said casing comprising a non-rotary 

